Guide
MPLS vs SD-WAN over Fiber
SD-WAN over fiber replaced MPLS for most companies. Some traffic still justifies MPLS.
SD-WAN over fiber replaced MPLS for most companies. Some traffic still justifies MPLS.
What changed
MPLS was the way to connect sites when the internet was not dependable enough to trust. It gave a private, predictable path between locations with class of service built in.
It was also expensive, slow to provision, and rigid. Adding a site meant a carrier order and a wait measured in months.
Then business fiber got cheap and dependable, and SD-WAN learned to steer traffic across multiple cheap circuits intelligently. That combination did most of what MPLS did for a fraction of the cost.
Where each still wins
| MPLS | SD-WAN over fiber | |
|---|---|---|
| Cost per site | High | Low to moderate |
| Time to add a site | Weeks to months | Days once circuits are live |
| Path control | Carrier guaranteed | Application aware, dynamic |
| Failover | Needs a designed backup | Native across every available link |
| Cloud traffic | Backhauls, adds latency | Breaks out locally |
| Predictable latency | Strongest | Very good on fiber, varies off-net |
The hybrid most companies land on
SD-WAN over dual internet circuits at the branches. A small MPLS or dedicated cloud interconnect core for the handful of applications that genuinely cannot tolerate jitter.
That gets the cost profile of internet with the certainty of private transport where it earns its keep.
The part that decides the outcome
SD-WAN is only as good as the circuits under it. Two connections from the same carrier entering the building through the same conduit is one connection wearing a costume.
Insist on carrier diversity and physical path diversity. That is where the resilience actually comes from.
Common questions
Is MPLS dead?
No, but it is now a specialist tool rather than the default. New multi-site builds start with SD-WAN over fiber and add private transport only where something demands it.
Does SD-WAN need dedicated internet at every site?
No. Many designs run one DIA circuit plus one broadband circuit per site. The SD-WAN handles the difference in quality between them.